Plate clamping mechanism for printing machines



W. F. HUCK July 15, 1947.

PLATE CLAMPING MECHANISM FOR PRINTING MACHINES Filed Feb. 10, 1944 4 Sheets-Sheet. 1

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PLATE CLAMPING MECHANISM FOR PRINTING MACHINES Filed Feb. 10, 1944 4 Sheets-Sheet 2 INVENTOR M99344 W. F. HUCK July 15, 1947.

PLATE CLAMPING MECHANISM FOR PRINTING MACHINES Filed Feb. 10, 1944 4 Sheets-Sheet 3 lNyENToR Wmuam F: HUc.\

W. F. HUCK July 15, 1947.

PLATE CLAMPING MECHANISM FOR PRINTING MACHINES Filed Feb. 10, 1944 4 Sheets-Sheet 4 Patented July 15, 1947 PLATE CLAMI'ING MECHANISM FOR PRINTING MACHINES William F. Huck, Forest Hills, N. Y., assignor to R. Hoe & 00., Inc., New York, N. Y., a corporation of New York Application February 10, 1944, Serial No. 521,829

19 Claims.

This invention which relates to mechanism for securing printing plates to the form cylinder of a rotary printing machine and more particularly to a fluid actuated means for operating the mechanism, was disclosed in part, in application Serial Number 466,987, filed November 26, 1942, of which vide an improved plate clamping mechanism having means for adjusting the plate clamps whereby they may be adapted to clamp plates which vary in Width to a considerable extent.

A further object is to provide an improved plate clamping mechanism wherein plate lifting means is included to loosen the plates from the cylinder when the plate clamps are released. I

It is also an object of this invention to provide a printing plate clamping mechanism of generally improved construction, whereby the device will be simple, durable, and inexpensive in construction, as well as convenient, practical, serviceable, and efiicient in its use.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood that various changes in the precise embodiment of the invention herein disclosed may be made within the scope of the claims without departing from the spirit of the invention.

A preferred embodiment and a modified form of the invention are illustrated in the accompanying drawings, wherein:

Figure 1 is a plan view of a form cylinder having printing .plates clamped thereon by the plate clamping mechanism of this invention;

and taken in the direction of arrows 6 of Figure 3;

Figure 6A is a fragmentary sectional view taken on the line BA-BA ofFigure 6 and showing the plate clamp guide rods;

Figure 7 is a fragmentary sectional view taken on the line l'| of Figure 6 showing a locking screw in unlocked position;

Figure 8 is an end view of a form cylinder having a plate clamping mechanism of somewhat modified form;

Figure 9 is an enlarged fragmentary surface view of a portion of the cylinder shown in Figures 8 and 11, taken in the direction of arrow 9 of Fi ure 8;

Figure 10 is a sectional view taken on the line In of Figure 8, showing certain parts of the plate clamping mechanism in position after unclamping a relatively wide plate, and showing the plate lifting means in raised position after releasing the unclamped plates from the cylinder;

Figure 11 is a sectional view taken generally on the broken line Il-ll of Figure 8, showing other parts of the plate clamping mechanism in position after unclamping a relatively wide plate, and in the lower portion, showing the plate lifting means in its position when a plate is clamped;

and

Figure 12 is a sectional view taken on the line l2--t2 of Figure 8 and showing parts of the plate clamping mechanism in position to clamp relatively narrow plates.

As illustrated in Figure 1 of the drawings, a form cylinder I l is arranged to carry eight semicylindrical printing plates, the plates being arranged four lengthwise of the cylinder and two plates around the cylinder. Inner plates 12 and 13, are positioned on each side of the middle of the cylinder and arranged in the usual staggered relation, while outer plates l4 and I5 are positioned two at each end of the cylinder and each in alignment with an adjacent inner plate.

The adjacent straight edges of the plates of each pair are spaced apart and held upon the cylinder II by the usual margin bars 2| secured to the cylinder by screws 22. The adjacent curved edges of the inner plates l2 and I3 are held on the cylinder and spaced apart by a center clamp ring or clip 23. The clamp ring 23 is seated in a peripheral groove 24 formed in the cylinder II and is secured therein by screws 25 threaded into the cylinder H.

The adjacent curved edges of inner and outer plates, l2, l4, and l3, l5, respectively, are spaced 3 6A), in this instance twelve rods 33 being pro vided for each clip 26. The rods 33 extend lengthwise of the cylinder and across the peripheral recess 32 with their ends disposed in holes 34 provided in semi-annular guide rod supports 35 and 36 (Figures 4, and 6A), to receivethem.

The outer surface of the guide rods 33 is shaped to conform with the peripheral surface of the cylinder II to engage the underside of'the' plate. 1

The supports 35 and 36 are secured in the recess 32 by screws 31 passing through the guide rods 33 and into the cylinder H. such that the inner clips 26 slide on these guide rods axially in respect to the cylinder, their movement being within the recess 32, and between the supports 35 and 36. Thus a plate 12 or |3 may be clamped between a clip 26 and the ring 23, or :be released'from such clamped position.

As-herein shown four plate clip connecting rods 38, extend through clearance holes 39 in the cylinder (Figures 3, 4 and 6). Four of these rods are provided for each clip ring 26. They have their inner ends threaded and are screwed into the inner plate clips 26. The outer end of each offthe connecting rods 38 has a screw-driver slot 4|, by which the rod 38 may be rotated to adjust the position of the clip 26 within a certain range, to suit the width of th printing plates to be used.

Means to lock the connecting rods 38 against rotation and thereby retain the adjustment of the clip 26, is shown in Figures 6 and '7, and includes a plurality of flat surfaces 42 cut on each rod 38, and adapted to be engaged by the periphery of a lock screw 43, screw-threaded into the cylinder I I. The lock screw is provided with a cross-slot 44 on its periphery in alignment with the rod 38 whereby, when it is turned in position disposes this slot 44 adjacent the rod 38, and the latter may be rotated to adjust the clip 26, but when the lock screw is turned to present its periphery against oneof the flat surfaces 42, the rod 38 is prevented from turning.

The cylinder I is provided with an annular recess 45 at each end to receive a pair of semi-annular spring retainers .46, each having a radially extending flange 41 on its periphery which seats upon the respective cylinder end and is secured thereto by screws 48. A bore 49 is provided in the retainers 46, andreceives a pair of arcuate thrust membersoryokes'E I, each having a semi-cylindricalportion 5'2'fitte'd to slide in the bore 49 of the adjacent retainer 46. Each yoke 5| also has a portion 53 extending toward and surrounding the respective shaft end l8 or I9, and a flange portion 54 extending radially therefrom over the r flange 41 of the spring retainer 46. An arcuate outer plate clamping member or clip 55 extends from each flange portion 54 over the periphery of the cylinder H, and is adapted at its edge 56, to engage anadjacent beveled edge 3| of an outer p1 ate |4 or l5. H

s The connecting rods 38 pass through the flange portion 54 of the thrust yokes 5| and are reduced in diameter at this portion to form ashoulder 51 which, when only an inner plate is to be clamped,

isv engaged by the flange portion 54. 1 Thus when a thrust yoke 5| is moved axially along the, cylinder I, it moves the plate clip 26 against an inner plate l2 0r l3 and clamps it betweenthe clip 26 and the clamp ring 23. When both an outer and an inner plate are mounted. adjacently on thecylinder, the shoulders 51 are slightly spaced from the flange 54 so as not to be engaged v thereby when the latter is moved. .A nut 58 is screwthreaded on the outer end of each rod 38 The arrangement is 'A look nut 59 is provided to lock the nut 53 in "its adjusted position.

Each thrust yoke 5| is moved inwardly and axially'along-the. cylinder H by springs 6|, there beingffive such springs as herein shown for each yoke; Each of the springs 6| is disposed in a bore .62, formed in the cylinder II to receive it, and

reacts between a spring retainer 46, and a piston 63 secured on a piston rod 64. The piston rod 64 extends through the spring 6| and the retainer 46-and is secured at its'outer end to the thrust yoke5| by a screw 65. There are thus five piston rods' connected' toeach thrust yoke. A packing cup 65;of leatheror similar material, is clamped against eachpiston 63 by a nut 61 screw-threaded uponthe piston rod 64. The piston cup 66 forms a fluid-tight joint against the Well of the bore 62.

The inner end of each of the five bores 62 is connected by a port 68 to a passage 69 extending axially in the cylinder shaft end I8 or I9 and sealed at its outer end preferably by a plug 1|. Each of the ports 63 is preferably drilled through from the periphery of the cylinder and sealed by a plug 12, as indicated in Figure 4. A hole 15 communicates with each passage 69 to provide an inlet and vent for the bores 62 with which the passage is connected, and it is arranged to receive a connection or terminal fitting 13, having a bore 14. A hose or tube having a suitable terminalfitting 16, preferably including an automatic valve of the type used on automobile tire inflating equipment, is connected to a source of compressedair or other suitable fluid. It is preferable that the bore 14 in the fitting 13 be made relatively small or constricted at some point, to prevent a too rapid flow of air into, or out of the bores 62, in orderfto avoid too rapid operation one of the thrust yokes 5| and its outer plate clamping member 55 away from the end of the cylinder and thereby move the outer and inner plate clamping members 55 and 26 into position to receive plates-I2 and M or 3 and I5. During its movement outwardly the flange 54 moves the outer clip 55 farther away from the inner clip 26, and then engages the nut 58 and through the rod 38 moves the inner clip 26 farther away from the clamp ring 23, thereby preparing the cylinder toreceive an inner and an outer plate. A plurality of stop studs 11, two being herein shown, are screw-threaded into each yoke 5|, to limit theoutward movement of the yoke to the extent indicated by dotted lines in Figure 4. When so moved, the studs 11 strike against a, collar 18 secured to the machine frame and surrounding the shaft end |8 or |9.

With the plate clamping mechanism thus in the open position, an inner plate |2 or |3 is placed on the cylinder with its inner edge against the ring 23, and the outer plate I4 01'' l5 is placed on the cylinder between the inner and outer clips 26; and 55. The. host terminal 16 is then removed from the fitting 13, disconnecting the air supply anism hereinbefore described and allowing the air to escape'from the bores 62, whereupon the springs 6| act on the yoke 5| to force the outer clip 55 into engagement with the outer plate, moving it into engagement with the inner clip 26, which then moves into engagement with the inne plate and presses it against the ring 23, thereby securely clamping both plates and holding them under a spring pressure that is maintained constant, notwithstanding any tendency of the clips to loosen due to their becoming embedded in the edges of the plates during prolonged operation.

' When it is desired to clamp only an inner plate H or I2, no adjustment or deviation from the procedure when both inner and outer plates are used is necessary, because the rods 38 perform the same function in respect to the operation of the inner clip 26 that would be performed by an outer plate I4 or I5 if it were present. The pressure of the thrust ring exerted against the shoulders 51 and the rods 38, moves the inner cli 26 into locking engagement with the inner plate, although in this instance, the thrust yoke 5| moves a slightly greater distance than when an outer plate'is used, this distance being the small clearance shown between the shoulder 51 and the inner side of the flange 54 in Figure 4.

When air pressure is applied to the pistons 63 the outer clip 55 first moves away from the plate I4, a distance sufficient to provide clearance for the removal of the plate. At this point the nuts 58 engage the flange 54 and the rods 38 draw the inner clip 26 and the plate I4 away from the plate l2, thereby providing sufiicient clearance between the clamping members and the plates so that either or both plates may be removed.

Where a provision for a greater range in plate width, than is possible with the clamping mechis desired, the clamping mechanism, shown in Figures 8 to 12 may be employed, In this form, which is best shown in Figure 11, plate clip connecting rods 38 correspond with the rods 38 of Figure 4, and the inner ends of the rods 38' are screw-threaded into a semi-annular clip 26'. The rods 38' extend lengthwise of the cylinder H through grooves 19 and their outer ends project beyond the main body of the cylinder H and pass through holes provided in lugs 80 that are spaced around the inner surface of outer semi-annular plate clips 8| and formed integral therewith. The inner surface of the outer clips 8| conforms to the outer surface of the cylinder II, and the lugs 80 eX- tend radially inward from this inner surface and are fitted to slide in slots (Figure 9), formed .are secured thereon. The rods 38' are flattened at 86 to provide a wrench engaging surface to be used when making adjustments. An intermediate portion of the rods 38' is enlarged in diameter to provide a shoulder 51 corresponding to the shoulder 51 of the form shown in Figure 4.

In order to provide for adjustment between the clip ring BI and the piston 63, the inner surfaces of. the lugs 80 are provided with tongues 93 and 94 adapted to be selectively seated in grooves 95 and 96 provided in the periphery of the yoke orithrustmember -8|. As shown at the upper left hand portion of Figure 11, the tongue 94 is seated in the groove 95.to clamp comparatively lon plates and. the tongues 93 and 94 as shown in Figure 12, are seated in the grooves 95 and 96 respectively to clamp shorter plates. Three rows of holes 90, 9| and 92 extend through the outer clip 8| and. its lugs 80. When the tongue 94 is seated in the groove 95 (Figure 11), the screws 88 are placed in the holes 9| and 92 and when the tongues 93 and 94 are seated in the grooves 95 and 96 respectively (Figure 12), the screws 88 are placed in holes and 9|.

In the form shown in Figures 8 to 12, each piston rod 64 is fitted to slide in a hole provided in a semi-annular spring retainer I00 which is secured in the cylinder H' by screws |0| (Figure 11), and a spring 6| reacts, as in the previously described form, between each of the pistons 63 and the spring retainer I00. In this form the piston rods 94' each have a threaded portion I02 that engages one of several threaded holes provided in the yokes 81 and is secured thereto by a lock nut I03. A wrench engaging section I04 is provided at the extreme outer end of each of the rods 64 whereby each piston may be adjusted in respect to its yoke.

It will be seen that the form of the invention shown in Figures 8 to 12, in addition to providing means for moving the clip 8| the distance required for properly clamping and unclamping the plates, also provides means for shifting the plate clips with respect to the yokes 81 to effect a coarse adjustment, and means for adjusting the position of the yokes with respect to the pistons, to effect an additional and fine adjustment.

Means whereby the plates are freed from the plate clamping members and raised from the cylinder each time the clamping mechanism is released are shown in Figures 8, 10 and 11 and include plate lifting dogs H9 and H5 which are depressed when the plate clamps are closed, as shown in the lower portion Of Figure 11, but when the plate clamps are released, the dogs H0 and H5 engage the under side and the inner edge of each plate and moving with the plate clips, ride up inclined grooves or guides, moving the plates away from the center clip ring and the inner clip, and lifting their inner edges from the cylinder as shown in Figure 10, and the upper portion of Figure 11. The lifting dogs I II) for the outer plates l4 and I5, each rides in an inclined groove H2 formed in the inner clip 26' and is secured on the inner end of a rod H3 which extends through a hole provided in a small lug 98, which like lugs 80, is formed as a part of the outer clip 8|. The outer end of the rod H3 is threaded and fitted with lock-nuts H4, to provide for adjustment that is required when a change is made to plates of a diiferent width.

The plate lifting dogs H5 which act on the inner plates I2 and I3 are operated through a rod H8 that is secured to a dog H5, and extends through a bearing post H9 and an L-shaped connecting link I29. The outer end of the rod H8 is threaded to receive adjusting nuts |2|. The link I20 is pivotally connected to the dog H0. When the dog H0 is moved, the link I20 will engage the inner nut |2| and move the dog H5 up an inclined guide H6 thereby freeing the plate |2 from the clamp ring 23 and raising it as shown in Figure 10, and in the upper portion of Figure 11.

When air pressure is applied to the piston '63 in the form of the invention shown in Figures .8 to 12 the outer clip 8| is moved away from'the plate I4 and the nuts :82 and H4 engage the lugs 80 and 98 respectively. This acts on the inner clip :26 the same as in the form shown in the Figures 1 to '6 and also moves the rod H3 and the dog H to raise the inner edge of the plate [4 toward the position shown in the upper portion of Figure 11. The movement of the inner clip 2 6', acting through the link I20 and rod H8, also moves the dog H5 to raise the inner edge of the plate l2 to the position shown in Figure and the upper portion of Figure 11. When the air pressure is removed the outer clip moves into engagement with the outer plate pushing it toward the inner clip and sinking the dog H0 into the cylinder. The outer plate meanwhile engages the inner clip which is moved into engagement with the inner plate, and further movement brings the inner plate into engagement with the center clip ring meanwhile sinking the dog H5 and finally locking the plates.

It will be seen that the operations of clamping and unclamping printing plates with the mechanism illustrated in Figures 8 to 12 is essentially the same as with the mechanism'illustrated in Figures 1 to 6. The form shown in the Figures 1 to 6 is simpler, but the form shown in Figures 8 to 12 provides for clamping both wide and narrow plates, and is arranged to loosen the plates from the cylinder when they are unclamped.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the claims rather than to the foregoing description to indicate the scope of the invention.

What I claim is:

1. In a, plate clamping mechanism for securing a printing plate upon the form cylinderof a printing machine, a stationary first plate clip, a slidable second plate clip positioned on the cylinde for movement to clamp a plate between it and the first clip, a connecting rod extending axially along the cylinder and adjustably connected to the second clip, the rod being adjustable from the end of the cylinder to adjust the position of the second clip, spring means carried by the cylinder and connected to the rod to move the rod and through it the second clip toward the first clip to clamp an inner plate, and fiuid pressure actuated means carried by the cylinder to move the rod and through it the second clip away from the first clip to release a plate clamped therebetween.

2. In a, plate clamping mechanism for securing inner and outer plates upon the form cylinder of a printing machine, a stationary first plate clip, a slidable second plate clip positioned on the cylinder fo movement to clamp a plate between it and the first clip, a, third plate .clip movable axially of the cylinder to clamp a plate between it and the second plate clip, a connecting rod extending axially along the cylinder and connected to the second plate clip, means to move the third plate clip to clamp a first plate between r inner and outer plates upon the form cylinder of aiprinting machine, a stationary first plate clip, a slidable second plate clip positioned on the cylinder for movement ;to clamp a plate between it and the first clip, a third plate clip movable axially of the cylinder to clamp a plate between it and the second plate clip, a connecting rod extending axially along the cylinder and adjustably connected to the second plate clip, said rod being operable from the outside of an end of the cylinder to adjust the position of the second clip, means to move the third plate clip to clamp a, first plate between it and the second plate clip and through the first plate to move the second plate clip to clamp e, second plate between it and the first plate clip, means to withdraw the third plate clip to release the first plate, and means adjustably mounted on the outer end of the connecting rod and engageable by the third plate clip to draw back the second plate clip and release the second plate.

4. In a plate clamping mechanism for securing inner and oute plates upon the form cylinder of a printing machine, a stationary first plate clip, a slidable second plate clip positioned on the cylinder for movement to clamp a plate between it and the first clip, a third plate clip movable axially of the cylinder to clamp a plate between it and the second plate clip, a connecting rod extending axially along the cylinder and adjustably connectedto the second plate clip, the rod being operable from the outside of an end of the cylinder to adjust the position of the second clip, spring means carried by the cylinder to move the third plate clip to clamp a first plate between it and the second plate clip and through the first plate to move the second plate clip to clamp a, second plate between it and the first plate clip, fluid pressure actuated means carried by the cylinder to draw back the third plate clip to release the first plate, and means adjustably mounted on the end of the connecting rod extending beyond an end of the cylinder and engage'able by the third plate clip, upon release thereby of the first plate, to draw back the second plate clip and release the second plate.

5. In .a plate clamping mechanismifor securing a, plate on a form cylinder of la, printing machine a first plate clip arranged to slide axially along the cylinder and to engage thezinner edge of .the plate, asecond plate'clip arranged to move axially of the cylinder and to engage the outer edge of the plate to clamp it between the second clip and the'first clip, a connecting rod extending from outside one end of the cylinder to the first plate clip to move it toward the first plate clip and clamp a plate therebetween, and fluid pressure actuated means carried by the cylinder operable to withdraw the second plate clip to release a clamped plate.

6; In a plate clamping mechanism for securing a plate on a form cylinder'of a printing machine, a first plate clip arranged to slide axially along the cylinder and to engage the inner edge ofthe plate, a second plate clip arranged to move axially of the cylinder and to engage the outer edge of the plate to clamp it between the second clip and the first clip, a connecting rod extending from outside one end of the cylinder to the first clip, being adjustably securedto the first plate clip and operable from outside an end of the cylinder to adjust the position of the first plate clip axially of the cylinder, means to lock the connecting rod in clip adjusted psition,- spring means carried by the cylinder and adapted to act on the second plate clip to move it toward the first plate clip and clamp a plate therebetween, and fluid pressure actuatedmeans carried by the cylinder operable to withdraw the second plate clip to release a clamped plate.

'7. In a plate clamping mechanism for securing a'plate on a form cylinder of a printing machine, a first plate clip arranged to slide axially along the cylinder and to engage the inner edge of the plate, a second plate clip arranged to move axially of the cylinder and to engage the'outer edge of the plate to clamp it between the second clip and the first clip, a connecting rod extending from outside one end'of the cylinder to the first clip, being adjustably secured tothe first plate clip and operable from outside an end of the cylinder to adjust the position of the first plate clip axially of the cylinder, means to lock the connecting rod in clip adjusted position, spring means carried by the cylinder and adapted to act on the second plate clip to move it toward the first plate clip and clamp a plate therebetween, fluid pressure actuated means carried by the cylinder operable to withdraw the second plate clip to release a clamped plate, and means adjustable axially on the rod and extending outside one end of the cylinder to position it for engagement by the second clip when the plate is released to draw the first clip toward the end of the cylinder.

8. In a plate clamping mechanism for securing inner and outer plates upon the form cylinder of a printing machine, a stationary first plate clip, a slidable second plate clip positioned on the cylinder for movement to clamp a plate betweenit and the first clip, a connecting rod extending axially along the cylinder and adjustably connected to the second clip, the rod being operable'from outside of an end of the cylinder to adjust the position of the second clip, spring means carried by the cylinder and connected to the rod to move the rod and through it the second clip toward the first clipto clamp a plate, a fluid operated device carried by the cylinder and connected to the rod to move the second clip away from the first clip to release a plate clamped therebetween, a duct connecting with the fluid operated device and having a vent, and a tube connected to a supply of fluid under pressure and having a terminal member connectable to the vent.

9. In a plate clamping mechanism for securing a plate on a form cylinder of a printing machine, a first plate clip arranged to slide axially along the cylinder and to engage the inner edge of the plate, a second plate clip arranged to move axially of the cylinder and to engage the outer edge of the plate to clamp it between the second clip and the first clip, a connecting rod extending from outside one end of the cylinder to the first clip, the rod being adjustably secured to the first plate clip and operable from outside an end of the cylinder to adjust the position of the first plate clip axially of the cylinder, spring means carried by the cylinder and adapted to act on the second plate clip to draw it toward the first plate clip and clamp a plate therebetween, fluid pressure actuated means carried by the cylinder and operable to withdraw the second plate clip to release a clamped plate, a duct connecting with the fluid operated device and having a vent and a tube connected to a supply of fluid under pressure and having a'terminal member connectable to the vent.

10'. In a plate clamping mechanism for securinginner and outer plates upon the form cylinder of a printing machine, a stationary first plate clip, a slidable second plate clip positioned on the cylinder for movement to clamp a plate between it and the first clip, a third plate clip movable axially of the cylinder to clamp a plate between it and the second plate clip, a connecting rod extending axially along and beyond the cylinder and adjustably connected to the second plate clip, the rod being operable from the outside of an end of the cylinder to adjust the position of the second clip, spring means carried by the cylinder to move the third plate clip to clamp a first plate between it and the second plate clip and through the first plate to move the second plate clip to clamp=a second plate between it and the first plate clip, a fluid pressure actuated means carried by the cylinder to withdraw the third plate clip and release the first plate, a duct connecting with the fluid operated device and having a vent, a tube connected to a supply of fluid under pressure and having'a terminal connectable to the vent, and means adjustably mounted on the end of the connecting rod extending beyond the cylinder and engageable by the third plate clip, to withdraw the second plate clip and release the second plate.

11. In a plate clamping mechanism for securing a printing plate on a form cylinder of a printing machine,'the said cylinder having a recess extending peripherally thereof, guide rod supports having guide rods secured in the recess and parallel to the axis of the cylinder, an arcuate plate clip slidable on the guide rods and adapted to engage the under side and a beveled curved edge of the plate, and means to move the plate .clip toward aand from the edge of a, printing plate.

12. In a plate clamping mechanism for securing a printing plate on a form cylinder of a printing machine, the said cylinder having a recess extending peripherally thereof, guide 'rod' supports having guide rods secured in the recess and parallel to the axis of the cylinder, an arcuateplate clip slidable on the guide rods and adapted to engage the underside and a beveled curved edge of. the plate, and means to move the plate clip toward and from the edge of a printing plate, the surface of the guide rods farthest from th'e cylinder axis being shaped to conform with the peripheral surface of the cylinder to engag the under side of the plate.

13. In a plate clamping and releasing mechanism for a printing machine, first, second, and third plate clamping members, means for moving two of the plate clamping members to clamp and alternatively to release plates, a first plate lifting mechanism associated with the second plate clamping member to lift a plate and release it from the second plate clamping member, a second plate lifting mechanism associated with the third plate clamping member to lift another plate and release it from the third plate clamping member, means for operating the first plate lifting mechanism from the first plate clamping'mernber, and means for operating the second plate lifting mechanism from the first plate lifting mechanism.

14. In a plate clamping and releasing mechaanism for a printing machine, first, second, and third plate clamping members, means for moving two of the plate clamping members, a first plate lifting mechanism associated with'one of the plate clamping members, a second plate lifting mechanism associated with another of the plate clamping members, and means connected to one end of the clamping member for operating the plate lifting mechanismsto lift one edge of each plate from th cylinder and simultaneously move the plates from contact with the plate clamping members.

15. In av plate clamping mechanism for securing and releasing printing plates on a form cylinder of a printing machine, a stationary center clamp ring, a movable outer plate clip, a movable inner plate clip, a first means arranged to lift andmove a plate from contact with the center clamp ring, and a second means arranged to lift and move a plat from contact with the inner plate clip, the second means being caused to function by a movement of the outer plate clip, and the first means being caused to function by a movement of the second means.

16. In a plate clamping mechanism for securing and releasing printing plates on a form cylinder of a printing machine, a first clip for engagingv one edge of a plate, a second clip for engaging an opposite edge of the plate and having a recess with an inclined groove, and a plate lifting dog operably connected to the first clip and having a portion cooperating with the inclined groove to lift and move the plate away from the second clip when the first clip is moved to release the plate.

17. In a plate clamping mechanism for securing and releasing 9, printing plate on a form cylinder of a printing machine, a first clip for clamping one edge of the plate, and having an inclined recess, a plate lifting mechanism operably connected to the first clip and having a portion positioned in the recess, in the second clip whereby when the releasing mechanism is operated, the lifting mechanism will slide in the inclined recess disengaging the plate from the second clip and lifting the plate from contact with the cylinder.

18:. In a printing machine, a form cylinder having a plurality of longitudinal bores arranged to receive pistons, a thrust member, threaded piston rods connecting the thrust member with the pistons and providing means to adjust the spacing between the pistons and the thrust member, a plate engaging clip arranged to be secured to the thrust member in a plurality of positions to adjust the spacing between the plate clip and the thrust member and thereby additionally adjust the spacing between the plate clip and the pistons, spring means acting on the pistons to move the plate clip in one direction to clamp a plate, and fluid pressure means acting on the pistons to move the plate clip in the opposite direction to release the plate, whereby printing plates varying considerably in size may be clamped on the cylinder.

19., In a plate clamping'and releasing mechanism for a printing machine, first, second and third plate clamping members, a spring, for moving the. first plate clamping member to clamp plates, at fiuid operated means for moving the first plate clamping member against the pressure of the spring, a means for moving the second plate clamping member when the first plate clamping member is moved, a first plate lifting mechanism associated with the second plate clamping; member, means for operating the first plate lifting mechanism from the first plate clamping member, a second plate lifting mechanism associated with the third plate clamping member, and means for operating the second plate lifting mechanism from the first plate lifting mechanism.

WILLIAM. F. HUCK.

REFERENCES CITED The following references are of file of this patent;

UNITED STATES PATENTS record in the 

